Analgesic thiomorpholins, their preparation, and pharmaceutical compositions containing them

ABSTRACT

Analgesic compounds are of the general formula (I): &lt;CHEM&gt; in which, R&lt;1&gt; and R&lt;2&gt; each represents hydrogen or C1-C6 alkyl, or R&lt;1&gt; and R&lt;2&gt; together with the nitrogen atom to which they are attached form a heterocycle; E represents methylene, sulphur, oxygen or imino group optionally substituted with C1-C6 alkyl or aralkyl; ring A is aryl or heteroaryl ring, optionally substituted; R&lt;3&gt; is hydrogen or C1-C6 alkyl and R&lt;4&gt; is hydrogen or R&lt;3&gt; and R&lt;4&gt; together represent a group of formula (IV):  -(CR&lt;a&gt;R&lt;a&gt;)m-C(=Y)-      (IV) (wherein R&lt;a&gt; and R&lt;a&gt; is C1-C6 alkyl or hydrogen, up to a maximum of 3 alkyl groups, m is 1, 2, or 3, and Y is two hydrogens or oxygen); provided that when E represents a methylene group, then R&lt;3&gt; is a C1-C6 alkyl group or R&lt;3&gt; and R&lt;4&gt; together represent a group of the formula (IV).



